Abstract: A tire mold having a substantially elliptical base surface and a method for making a tire mold are provided. In one embodiment, a user selects a major axis length for the tire mold, then selects a ratio of the major axis length to a minor axis length. The tire mold is then formed with a substantially elliptical base surface defined by the first major axis and the selected ratio.

Abstract: A tire mold having a substantially elliptical base surface and a method for making a tire mold are provided. In one embodiment, a user selects a major axis length for the tire mold, then selects a ratio of the major axis length to a minor axis length. The tire mold is then formed with a substantially elliptical base surface defined by the first major axis and the selected ratio.

Abstract: A tire mold having a substantially elliptical base surface and a method for making a tire mold are provided. In one embodiment, a user selects a major axis length for the tire mold, then selects a ratio of the major axis length to a minor axis length. The tire mold is then formed with a substantially elliptical base surface defined by the first major axis and the selected ratio.

Abstract: A tire having a circumferential tread with segmented sipes is provided. In one embodiment, the tire has tread blocks with sipes having at least three segments. The sipe may include a first major segment, a second major segment, and a minor segment connected to both the first major segment and the second major segment. In alternative embodiments, the sipe may include three or more major segments, connected by a plurality of minor segments.

Abstract: A tire mold having a substantially elliptical base surface and a method for making a tire mold are provided. In one embodiment, a user selects a major axis length for the tire mold, then selects a ratio of the major axis length to a minor axis length. The tire mold is then formed with a substantially elliptical base surface defined by the first major axis and the selected ratio.

Abstract: A tire having sipes is provided. The tire includes a circumferential tread configured with at least one rib bound by at least one groove. The rib has a plurality of sipes that extend from the groove into the rib wherein one or more of the sipes narrow in a direction from the groove into the rib.

Abstract: A curable rubber bladder stock containing esters of ricinoleic acid or derivatives thereof has reduced viscosity as compared to stocks containing castor oil. The rubber stocks of the present invention generally retain a very high percentage of the initial cure tensile strength and have improved modulus as compared to castor oil, both upon initial cure and upon aging. Lower viscosity and higher modulus of the rubber stocks of the present invention readily permit the production of thinner bladders. The bladders can fit within an article such as a tire during vulcanization of the tire as in an automatic vulcanizing press. Thinner bladders effect a greater heat rate and result in shorter cure times for articles such as tires. The esters of ricinoleic acid and derivatives thereof have the formula ##STR1## where R is H or ##STR2## where R.sup.1 is an aliphatic, preferably an alkyl, having from 1 to 12 carbon atoms, desirably from 1 to 4 carbon atoms, and preferably 1 carbon atom, i.e., methyl, and R.sup.

Abstract: The quality and useful life of curing bladders used in standard "Bag-O-Matic" tire vulcanizing presses is greatly improved by replacing the standard split two-piece core of the bladder mold with a unitary core which forms a disc-like rubber diaphragm below the core and integral with the rubber curing bladder at the periphery of the core. A unique base plate fits in the lower mold half below the core and has a grooved upper surface to hold the diaphragm in place so that the core can be removed manually or automatically with the assistance of internal air pressure.